Recovery drinks come in the form of nutritionally complete powders. Their combination of proteins, fats, carbohydrates, vitamins, minerals and sometimes herbs are designed to boost depleted glycogen (carbohydrate) stores and aid muscle tissue recovery by replenishing essential amino acids and other nutrients lost during hard exercise. They may also be used as liquid meal supplements or nutritionally complete liquid alternatives to solid foods.

Several years ago, while investigating diet drinks, a group of researchers from a major San Francisco nutrition company discovered that the right balance of carbohydrates and proteins produced a greater secretion of insulin into the blood than did either carbohydrates or proteins alone. A few years later, this group began to focus its attention on sports nutrition. During their investigation into the literature of biochemistry and physiology, they were struck by the fact that insulin is the body's natural biochemical trigger for stimulating carbohydrate uptake by the muscles - a process that aids in recovery and muscle rebuilding after hard exercise.

Based on their earlier work with carbohydrate-protein combinations, the group realized that it could develop a food supplement that would not only provide the building blocks for recovery but also turn on the metabolic switches to hasten the recovery and make optimal use of those building blocks. The group hypothesized that a combination of carbohydrates and proteins would stimulate the body's production of insulin and, by enhancing muscle glycogen resynthesis, would also allow the body to restore muscle energy faster - and increase recovery speed after exercise. Thus were recovery drinks born.

John Ivy, Ph.D., from the University of Texas in Austin, became interested in testing the new hypothesis. He conducted an independent study comparing three 16-ounce, post-exercise drink supplements: a recovery drink with its unique carbohydrate-protein combination formula (112.5g carbohydrates, 40.5g protein); a "protein" drink (40.5g protein); and a "carbohydrate" drink similar to the "carbo-loading" products on the market (112.5g carbohydrates). The subjects were nine trained cyclists, each of whom tested all three supplements on three separate occasions. Each athlete cycled to exhaustion under a protocol that reflected actual race conditions.

After every session, each cyclist drank one of the three supplement drinks immediately and again at two hours. Results from the study confirmed that the carbohydrate-protein combination elicited a greater insulin response in the blood than the carbohydrate or protein supplements alone. As a matter of fact, the recovery drink supplement insulin response was greater than the sum of the other two products. The study also measured each cyclist's muscle glycogen leve - -the body's store of carbohydrate. As was hypothesized by Ivy, the greater insulin levels produced by the metabolic optimizer actually led to a greater increase in the rate of muscle energy production in the four-hour period after exercise than either the protein or carbohydrate supplements alone.

Designed To Build and Repair Muscle

Recovery drinks provide a unique protein and carbohydrate blend formulated to increase the amount of the anabolic hormone insulin in the body for enhanced muscle rebuilding. Insulin is the body's principal anabolic "on-off" switch, moving into the bloodstream and setting the muscle-building system into motion. Once the anabolic mechanism is in high gear, recovery drinks then play another muscle-building role - providing protein needed to rebuild muscle and grow new muscle mass.

Recovery drinks can also contain other nutrients important to the athlete, including chromium and creatine. These latter nutrients enhance insulin's anabolic, body-repairing role. Research has shown that athletes who train hard may be low in these essential nutrients. As with standard high-carbohydrate drinks, an individual should consume 1g to 3g of metabolic optimizer powder per kilogram (2.2 pounds) of body weight within 30 minutes of finishing a hard exercise session. For example, a 150-pound cyclist would consume between 68g and 204g of powdered product after a long, hard training ride or race.

A High-Energy Supplement

Dietary surveys of many groups of athletes report high-energy intakes of carbohydrates, fats and proteins. The carbohydrate requirements of athletes in heavy training may be from 60 percent to 70 percent of the total calories eaten. However, adequate consumption of bulky, high-volume carbohydrates may be constrained by gastric discomfort. Long training sessions may further interfere with dietary intake by restricting the time available to prepare and eat meals and by reducing interest in food due to fatigue or suppressed appetite. The recovery drink, as an adjunct to dietary intake, offers the practical advantage of minimal food preparation and reduced bulkiness, as well as providing a high-energy and nutrient-dense intake. This may be of special interest to athletes with high-energy requirements or those in heavy training programs. Recovery drinks may also be used to boost the energy content of quick meals and snacks, a strategy that may be particularly useful to the traveling athlete whose training or competition may take him or her away from their normal food sources.

Pre-Event Meal

The athletic pre-event meal should satisfy the following criteria: (1) have no adverse effects on carbohydrate stores and possibly increase glycogen stores; (2) provide a relatively empty stomach at time of competition; (3) provide adequate hydration; and (4) cause no gastrointestinal problems. Most coaches recommend the intake of a pre-event meal two to four hours before competition, and athletes are encouraged to experiment with the type, timing and amount of food that fulfills these goals. Recovery drinks fit these suggested criteria of a quickly digested, practical pre-event meal, particularly for athletes whose nervousness might cause gastric problems. Most athletes can consume the supplement from two hours to 30 minutes before competition.

During Endurance Exercise

While being promoted primarily as pre- and post-exercise nutritional supplements, recovery drinks may have other advantages during endurance exercise. "Cyclists are also experimenting with recovery drinks during long road races (120 miles or more)," says Steve Hegg, U. S. Professional Road Cycling Champion. "Results show both that carbohydrates are an important fuel and that cyclists begin to use amino acids (protein) for fuel after carbohydrate stores become depleted. Carbohydrates and proteins from such products can spare the breakdown of muscle tissue by supplying protein in the later stages of exercise," adds Chris Carmichael, coaching director for the U.S. Cycling Team. Lastly, many of the newer recovery powder drinks are easy to mix with water, which makes them as convenient to use at the race site as standard powdered energy drinks. (Information from article by Edmund Burke in Nutrition Science News.)